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<head><meta charset="utf-8"><title>Possible CI speed-up · t-infra · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/242791-t-infra/index.html">t-infra</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/242791-t-infra/topic/Possible.20CI.20speed-up.html">Possible CI speed-up</a></h3>

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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/242791-t-infra/topic/Possible%20CI%20speed-up/near/233255353" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Flying-Toast <a href="https://rust-lang.github.io/zulip_archive/stream/242791-t-infra/topic/Possible.20CI.20speed-up.html#233255353">(Apr 06 2021 at 01:50)</a>:</h4>
<p>Does the CI (on linux &amp; macos) set the niceness of cargo processes? I'm curious if aliasing the <code>cargo</code> command to <code>nice -n -20 cargo</code> would speed up CI builds.</p>



<a name="233255856"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/242791-t-infra/topic/Possible%20CI%20speed-up/near/233255856" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/242791-t-infra/topic/Possible.20CI.20speed-up.html#233255856">(Apr 06 2021 at 01:57)</a>:</h4>
<p>What would you expect it to compete with? Nothing else should be running in our VMs really. I would guess that this would have very minor effects regardless, personally, but if someone wanted to try to add support and run some try builds to collect data I'm not entirely opposed.</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/242791-t-infra/topic/Possible%20CI%20speed-up/near/233268736" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> The 8472 <a href="https://rust-lang.github.io/zulip_archive/stream/242791-t-infra/topic/Possible.20CI.20speed-up.html#233268736">(Apr 06 2021 at 05:33)</a>:</h4>
<p>The kernel might be doing background work, but outcompeting that could make things worse if it's actually background work we need to happen.<br>
A different thing that can be tweaked besides niceness is increathe timeslice length, e.g. by scheduling it as <code>SCHED_BATCH</code>. But improvements from that tend to be miniscule unless you have an oversubscribed CPU, which we shouldn't have due to the jobserver.<br>
CI is also really noisy since it's cloud machines, sub-percent improvements get drowned in the noise.</p>
<p>Imo the only thing that could really help CI is improving core utilization by the way bootstrap executes tasks.</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/242791-t-infra/topic/Possible%20CI%20speed-up/near/233292505" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Pietro Albini <a href="https://rust-lang.github.io/zulip_archive/stream/242791-t-infra/topic/Possible.20CI.20speed-up.html#233292505">(Apr 06 2021 at 09:46)</a>:</h4>
<blockquote>
<p>CI is also really noisy since it's cloud machines, sub-percent improvements get drowned in the noise.</p>
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<p>macOS does not really run on cloud machines, it's on actual mac minis somewhere</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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